A199762 a(n) = (9*11^n+1)/2.

5, 50, 545, 5990, 65885, 724730, 7972025, 87692270, 964614965, 10610764610, 116718410705, 1283902517750, 14122927695245, 155352204647690, 1708874251124585, 18797616762370430, 206773784386074725, 2274511628246821970

Offset

0,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 0..900

Index entries for linear recurrences with constant coefficients, signature (12,-11).

Formula

a(n) = 11*a(n-1)-5.

a(n) = 12*a(n-1)-11*a(n-2).

G.f.: 5*(1-2*x)/((1-x)*(1-11*x)).

Mathematica

(9 11^Range[0, 20]+1)/2 (* or *) LinearRecurrence[{12, -11}, {5, 50}, 20] (* Harvey P. Dale, Sep 07 2023 *)

Prog

(Magma) [(9*11^n+1)/2: n in [0..30]];

Crossrefs

Sequence in context: A113330 A079157 A286974 * A078244 A233068 A237020

Adjacent sequences: A199759 A199760 A199761 * A199763 A199764 A199765

Keyword

nonn,easy

Author

Vincenzo Librandi, Nov 10 2011

Status

approved